This invention relates to a method for textile printing using an ink jet process where the textile has been treated with materials to improve the color intensity and waterfastness of the ink.
In the textile printing industry, many chemicals have been applied to cloth to improve the quality and permanence of the colors and patterns which are printed on the fabric. For example, polymeric compounds obtained by the reaction of epihalohydrin with a polyalkylene polyamine have been used as textile treatment agents for hydroxy group-containing fibers, such as cellulose, especially cotton, and nitrogen-containing fibers, for example polyacrylonitrile and natural or synthetic polyamides such as wool, silk or nylon. When used as pretreatment agents, the polymers improve the color yield of the subsequent dyeing and allow for shorter dyeing times. When used as aftertreatment agents, they improve waterfastness.
To create printed clothing, various printing methods such as roller printing, screen printing, transfer printing, etc. have been used. The conventional methods require preparation of print plates or screen plates. Because preparation of these transfer devices is expensive, it is not cost effective to prepare the print plates or screen plates unless the printed cloth is produced in large quantities.
The period of fashion for printed clothing is often quite short, and new printing plates with a different design have to be made at frequent intervals at great expense. In addition, changes in fashion can lead to large stockpiles of out-of-fashion prints. There is a need for a method of printing textiles in which patterns can be changed rapidly and inexpensively, so that the produced printed fabrics can be prepared in a timely manner and in batches small enough that they do not lead to large quantities of out-of-fashion prints.
In order to meet these needs, textile printing by an ink jet process has been proposed. There are difficulties in printing fabrics by the ink jet process, however. Fabrics are normally printed with a high viscosity liquid. High viscosity liquids are not appropriate for printing with the ink jet process, because they do not flow well enough to be applied through the ink jet nozzle. Low viscosity inks which are deposited onto fabric by the ink jet process are prone to spreading, because fabric does not retain ink very well. In addition, fabric often has texture, and the texture can increase the spreading of the ink on the fabric. Furthermore, even if the dye in the ink is deposited evenly, the levelling properties of the dye which is deposited by the ink jet process change with time, and the dye is often not fixed well onto the fabric. Considerable difficulty has been encountered in creating ink jet printed textiles which are washable without substantial degradation in color density.
Various methods of textile coating and treatment have been attempted to address these difficulties. For example, compounds such as starch, cellulose, gum arabic, and polyvinylacetate have been placed onto fabric before forming a pattern on the fabric with ink jet printing in order to reduce spreading of ink. Although the methods are an improvement over simply using uncoated fabric, the patterns are found to not be nearly as sharp as patterns produced with conventional printing technology, and the textiles are not washable without losing significant color intensity. There is thus a need in the art for a textile treatment process which produces washable and high quality textile prints which have been printed with an ink jet printing process.